Nonwoven Geotextiles act as a permeable separation, allowing water to pass while preventing soils and other material from passing. Medium weight nonwovens (7 oz. to 10 oz.) are typically used for erosion control and separation/drainage applications. Heavyweight nonwoven geotextiles (10 oz. to 16 oz.) are often used as a geomembrane cushion, placed above or below the geomembrane to protect it from puncture.